Proper pasture management leads to high quality, productive pastures that can supply excellent nutrition for horses. However, pasture management can be challenging because of continually changing environmental conditions and fluctuations in horse populations residing on the farm. Adopting good pasture management practices is increasingly important as stocking density or number of horses per acre increases. In most areas, pastures can be maintained with very little management at densities of 2 – 4 acres per horse. At higher animal densities, good management practices are necessary to maintain plant canopy cover and desirable plants. Without adequate pasture acreage, horse owners will need to limit turnout time to prevent overgrazing and supplement with hay to help meet equine nutritional requirements. The management practices, outlined in this fact sheet, can be adopted to help maintain healthy, productive pastures that benefit the horses, the farm, and the environment.
Proper fertilization is imperative to maintaining high quality forage in pastures. Soil nutrient levels and pH are extremely
variable form farm to farm. Therefore, it is important to accurately determine the nutrients and pH of the soil by performing a soil analysis. To obtain soil test kits and receive directions on how to collect a soil sample, contact your local Extension office or an analytical laboratory. After submitting the sample, the lab will provide a complete soil analysis, which will document soil nutrient levels and pH. The report will also provide recommendations for the application of fertilizer and lime.
Maintaining proper soil pH is essential for healthy forages. Soil pH is a measure of the acidity in the soil. A pH of 7 is neutral. A pH greater than 7 is basic, and less than 7 is acidic. Grass forages perform well in soils with a pH between 6 and 7. Acidic soils are detrimental to plant health and productivity because acid conditions limit the availability of the soil nutrients. Lime is basic in nature. Therefore, application of lime increases soil pH and makes the nutrients in the soil more available to the plant.
Plants also require nutrients for growth and reproduction. Soil test results identify nutrient deficiencies and provide nutrient recommendations for optimum crop production. The three primary nutrients included in the soil test report are nitrogen (N), phosphorus (P), and potassium (K).
For grasses, nitrogen is a critical nutrient for forage quality and growth. Adequate nitrogen is associated with a dark green color and vigorous, vegetative growth. Pale green or yellow color and poor growth is a symptom of nitrogen deficiency. Too much nitrogen applied at one time can cause animal health and water quality problems, so nitrogen applications should be divided into multiple, smaller applications.
Phosphorus and potassium are also vital nutrients. Phosphorus improves forage quality and root development. A well-developed root system increases the plant’s ability to acquire nutrients and water from the soil.
Potassium improves the plant’s ability to survive periods of stress such as drought or freezing winter temperatures and conditions. Potassium deficiency is characterized by poor growth, reduced disease resistance, and reduced winter-hardiness.
Mow Your Way to a Healthier Pasture
Mowing helps maintain a high-quality uniform pasture, and promotes tillering, which generates dense, leafy vegetation. In addition to maintaining quality and productivity of favorable species, mowing also helps prevent the growth of w**ds (It removes some w**d species and reduces the production of w**d seeds by others).
Mowing at the proper height is an important component in maintaining the health and survival of pasture grasses. Grasses store their energy reserves in the bottom few inches of the plant, so mowing too low reduces their reserves and the ability of the plant to re-grow. When mowing, maintain a forage height of 2 to 3 inches if the pasture is composed primarily of fine bladed short grass species, such as perennial ryegrass and bluegrass. For taller, higher yielding species such as orchard grass or timothy, mow to maintain a slightly higher level of 3 to 5 inches.
Reduce W**d Pressure
W**ds can be a serious problem in pastures because they compete with desirable forages for space, nutrients, light, and water. Some w**ds, if ingested, are toxic and harmful to animal health and should be eliminated. W**ds rarely out-compete healthy pasture grasses but they will quickly take over if the pasture is not management to ensure the growth of the grasses. It is important to address w**d issues prior to establishing a new pasture. In established pastures, the most effective w**d management technique is to maintain a healthy stand of grasses and legumes, which compete with the w**d seedlings. Good pasture management will help prevent w**d proliferation.
When w**ds become a continual problem, herbicide applications may be warranted. However the use of herbicides alone will not provide a permanent solution to w**d control. The conditions that caused w**ds to proliferate should also be addressed. Reseeding the pasture with desirable forages will hinder the re-establishment of w**d seedlings and promote the growth of grasses and/or legumes. It will be necessary to manage and maintain conditions that will promote forage growth.
The first step in any w**d control program is to identify the specific species of w**ds in your pasture. If you decide to use herbicides as a w**d management tool, it is very important to apply the right product because the efficacy varies by species. Plan all herbicide programs wisely. Remember that broad leaf herbicides will also eliminate desirable legumes, like clover and alfalfa, from pastures along with the w**ds. Most pasture herbicides available today do not have grazing restrictions and animals do not have to be removed from the pasture. However, label restrictions must be adhered to carefully. Many herbicides have forage reseeding restrictions and cannot be applied to new forage seedlings. Several labels restrict products from being used on pastures if the manure is collected and applied to gardens or broad-leaf crops. The label warns against potential damage that residual herbicide in manure can cause for sensitive broad-leaf plant species.
Before choosing an herbicide, it is important to identify the type of w**ds in the pasture because product efficacy varies by species. An herbicide that eliminates one w**d species might not have activity on another. In addition to selecting the correct product, it is important to apply the herbicide at the right time. Identifying the life cycle of the w**d ensures that the herbicide can be applied at the most vulnerable periods of plant growth.
W**ds differ in species, persistence, and life cycle. Perennial w**ds live more than one year and are dormant in the winter. The ideal time to control perennial w**ds is late summer when the w**ds are moving their food reserves into the roots. Canada thistle, curly dock, and milkw**d are examples of perennial w**ds that commonly grow in pastures.
Annual w**ds only live one year, but are prolific seed producers. The parent plant will die but the w**d seeds that are produced can germinate and produce many plants the following year. Annual w**ds exist as summer annual or winter annual w**ds.
Summer annual w**ds produce seeds in the summer. The seeds survive the winter and germinate the next spring. A thick, healthy stand of grasses should be able to compete and hinder growth of newly emerging w**d seedlings in the spring. If summer annual w**ds do become established, then the mature w**ds will be highly visible in summer, when the cool season grasses slow their growth due to hot, dry conditions.
Mowing can sometimes effectively reduce w**d seed production and will help reduce w**d pressure. It is a poor decision to use herbicides to eliminate summer annual w**ds in late summer because the plants have already dropped their seeds and are beginning to die. The ideal time to control summer annual w**ds with herbicides is in the spring, when the w**d seedlings are very small. Examples of some common summer annual w**ds are lamb’s quarters, ragw**d, and pigw**d.
Winter annual w**ds such as chickw**d and mustard also live one year, but germinate from seeds in late summer. Winter annual seedlings appear in pastures in early fall and persist as plants throughout the winter. Winter annual w**ds flower very early in spring, drop their seeds, and die. By summer, winter annual w**ds are no longer competitive in the pasture.
Since winter annual w**ds are present in spring and fall, when cool season grasses are rapidly growing, it is rarely necessary to control these w**ds. Healthy pasture grasses should be able to prevent the germination of winter annual w**d seeds and reduce the survival of any seedlings. If pasture growth is poor and the elimination of winter annuals is warranted, the best time to apply herbicide is late summer, after the w**d seeds have germinated.
Pastures Need Rest, Too
Rotational grazing systems improve the pasture productivity by allowing grasses to restore energy reserves required for growth. Developing a strategic plan to rest and rotate pastures, allows the manager to obtain more forage and greater use of multiple pastures.
Horses can cause significant damage to pastures. Hooves cause soil compaction and a running horse can trample and sheer off pasture plants. The precision of a horse’s lips and teeth allow horses to remove plants at ground level. Horses tend graze in the same location area repeatedly graze the same plants because of enhanced nutrition and palatability. Repeated intense grazing can damage parts of the plant necessary for regrowth and can eliminate plants from the pasture, reducing the concentration of high quality forage. Therefore, pasture rotation is essential to good pasture management practices.
Repeated, close grazing of grasses depletes energy reserves, reduces growth, and eventually kills the plant.
As stocking density increases, the implementation of a rotational grazing system becomes more important. Even a simple two-paddock system will produce results. To set up a two-paddock system, place one cross-fence across the pasture and rotate the horses between the two pastures.
Turn animals into the pasture when the grass is 7 to 10 inches tall and allow them to graze it down to 3 to 4 inches. A grazing system with more than two paddocks will provide additional improvements in the performance of the pasture.
Pasture Renovation
Pasture renovation is an effective way to improve stand density or introduce new species into existing pastures. Following a few simple management strategies will ensure the establishment of new seedlings.
Selecting the most appropriate time of year to seed the pasture greatly influences stand establishment. Spring and fall are ideal seasons to plant; however, fall is usually the preferred seeding time in Pennsylvania. Spring generally generates higher w**d competition and, in regions prone to drought, young seedling may succumb to the hot, dry summer conditions.
Proper soil preparation promotes good establishment. Soil tests are necessary to determine pH levels and nutrient needs.
Lime should be added at least six months prior to seeding.
There are two factors that greatly affect successful renovation: seed to soil contact and seeding depth. Planting seeds too deep is the #1 cause of forage seeding failure. The ideal seeding depth is ¼ inch. Seed to soil contact is the second cause of failure. In order to ensure seed germination, the seeds need to be in contact with and covered by soil.
If there is vegetation in the pasture that can compete with new seedlings, the horses should be allowed to graze the grasses as short as possible prior to reseeding. The pasture can also be mowed very short to suppress the existing vegetation. A third option is to use glyphosate herbicide to kill existing plants.
Seed can be randomly applied using a spinner seeder. To ensure seed to soil contact, the soil should be loosened using a spike harrow or set of discs. After broadcasting the seed, the pasture should be lightly harrowed to pull soil over the seeds. Another method of reseeding a pasture is to use a no-till drill. The drill cuts a slit in the soil, drops the seed and covers it with soil.
To ensure successful forage establishment, seeds need to be planted less than ¼ inch deep and soil needs to cover the seed, providing seed to soil contact.
Horses will need to be removed from newly seeded pastures until the new plants have at least 5 to 6 inches of growth and the root systems are strong enough to handle grazing pressure. Remember to adopt good management practices to protect the new stand and it will provide nutrition for your horse for many years to come.
DONNA FOULK
